Aeration is widely recognised as a vital practice in virtually all other sports' turf-maintenance programmes, but for now there is a diverse array of opinion on just how important it is for quality cricket surfaces.
"At the moment there are two schools of thought - some groundsmen like to aerate a lot and some don't aerate at all and still get good pitches," says Cranfield University lecturer Dr Iain James, who heads the Centre for Sports Surface Technology.
The centre is embarking on a four-year project to develop industry guidelines on aeration that will be backed up by solid experimental evidence from the field. The work is funded by the England & Wales Cricket Board, the Government and the Institute of Groundsmanship's (IOG's) 2012 Fund, recently renamed the Alex Millar Fund in honour of the institute's late chairman.
Some experiments are already underway while others are still being developed. The project started just over a year ago and James presented the initial findings at IOG Saltex 2009. The project will lead to guidelines being published in 2012/13.
"Our research will provide better guidance for groundsmen on what they are - and aren't - doing," says James. "It will allow them to allocate their time more effectively, leading to greater efficiency. That will be really important over the next few years as clubs try to use their scarce resources in the best way."
According to Simon Parsons, a doctoral student conducting much of the research: "There is not a lot of evidence behind much of what is said about aeration - the level of doubt in the industry is high. So we are trying to find a method to quantify what they say and find best-practice methods. We can aim for a similar impact to the rolling guidelines."
"But it is much more nebulous a question," points out Mark Bartlett, an academic fellow at the centre who, along with James, is the guiding force behind Parsons' work. "It is likely to follow on to other research - we won't be able to answer all the industry's questions."
Indeed, the team is keen not to overstate the importance of what it has discovered so far. All research needs a baseline but at present the team has only anecdotal evidence as to current industry practice. Cranfield's own grounds staff aerate their cricket pitches monthly in early to mid-winter but elsewhere regimes are thought to vary widely from club to club.
In order to establish a better picture of what the industry is currently doing, Parsons has put together a questionnaire for groundsmen, which is available to download at www.cranfield.ac.uk.
"We are aiming it at everyone just to find out what common practices are in terms of renovations and things," says Parsons. "We want to get a feel for whether or not practices are uniform across the country. We want to find out whether or not everyone has a horizontal break in their surfaces, for example."
Meanwhile, Parsons is conducting a wide range of experiments both in the lab and in the field in order to gain an overall view of the effects of aeration. These involve measuring - among other things - moisture content, impact resistance, resistance to penetration and microbial communities within the soil.
Early results of field tests using spiking, drilling, air or water injection and solid tines show that some methods can help in making the soil easier to penetrate.
However, there remains an argument that natural aeration - through sea- sonal shrink-and-swell of clay loam - may lessen the need for mechanical methods in certain sites. In some tests, using a spike roller was found to increase the energy needed to penetrate the soil or even make it more compacted.
While Bartlett says that natural shrinkage and swelling can be all the aeration some pitches need, he says there are lots of different reasons to aerate - it is not just about alleviating compaction.
To gain a better overall picture, the team is looking at the effects of a wide range of treatments on the soil and by running the tests over a four-year period the team hopes to produce guidelines that account for as much variability as possible. But challenging weather so far has made it harder to assess their effectiveness.
Parsons says: "We have tried to keep it as standard as possible. We have got plant experiments in the lab looking at more troublesome conditions.
"We have two major outdoor experiments at Cranfield looking at high- and low-clay pitches to look at density and also at soil atmosphere. We are using micro-porous tubes buried under the pitch, linked by a pipe to an extraction chamber, which allows us to measure the concentration of gas without having to disrupt the surface."
The method has evolved from the use of suction tubing and allows researchers to take many more readings in the course of a single day.
"There is no lag effect so you are not recording things that happened six hours ago," says Parsons.
Meanwhile, work in the lab aims to overcome the difficulties of measuring many of the variables in the field.
Though there is a broad range of issues the team are attempting to tackle, there are inevitably questions that will go unanswered.
"We would like to look at the compacting effect of putting tine into the soil," says Bartlett. "But it's all about fitting in what we can during the time available. We can see the framework but at the moment it consists of more questions than answers."
GUIDELINES ROLLED OUT
Cranfield University has already produced guidelines on cricket pitch rolling that optimise efficiency.
Based on extensive research and backed up by rigorous testing, the university identified that many wickets were being rolled far too often.
The guidelines have won acclaim, with the IoG recently bestowing on them an award for best innovation in grounds maintenance. And recommendations are already having an impact the world over, with more than 1,000 people downloading the guidelines so far.
The result of four years of research by Cranfield University's Centre for Sports Surface Technology was commissioned by cricket's governing body, the England & Wales Cricket Board (ECB).
Centre leader Dr Iain James also headed up the research. He said if all the clubs in England and Wales were to target their rolling using the guidelines, the saving in rolling time would amount to over 700,000 hours per year, while fuel savings would reduce cricket's carbon footprint by the equivalent of a small housing estate.
As with the current study on aeration, the rolling study built on the findings of a questionnaire, answered by 100 ECB and IoG grounds staff. This found a very wide range in rolling practices, with some groundsmen rolling as many as 280 times a year and others as few as five.
The guidelines, aimed at both professional and volunteer grounds staff, are available to download from the Cranfield website at www.cranfield.ac.uk.